What year and model kia? Are you using oem or aftermarket sensors? Thanks.
were do I click
If sensor has been replaced with oem part then next step is to have resistance tests done on wiring going to sensor...There are two wires that need to be tested...wiring should be under 5 ohms if not replace wiring/connector as needed...If you have any exhaust leaks that can also cause this code. Here are troubleshooting instructions from manual. Let me know if you have questions, thanks.